Expanding Storage Capacity

To add storage capacity to a file system, create a concatenation volume. To add storage capacity to an existing stripe, create a concatenated stripe volume.

How to Expand Storage Capacity for Existing Data

Caution - Do not create volumes larger than 1Tbyte if you expect to run the Solaris software with a 32-bit kernel. Additionally, do not create volumes larger than 1 Tbyte if you expect to use a version of the Solaris OS prior to the Solaris 9 4/03 release. See Overview of Multi-Terabyte Support in Solaris Volume Manager for more information about multi-terabyte volume support in Solaris Volume Manager.

Before You Begin

Check Prerequisites for Creating Solaris Volume Manager Components and Background Information for Creating RAID-0 Volumes.

Unmount the file system.
```
# umount /filesystem
```
To create a concatenation, use one of the following methods:
- From the Enhanced Storage tool within the Solaris Management Console, open the Volumes node. Choose Action⇒Create Volume, then follow the instructions in the wizard. For more information, see the online help.
- Use the following form of the metainit command:
```
# metainit volume-name number-of-stripes components-per-stripe component-names
```
  volume-name
  
  Specifies is the name of the volume to create.
  
  number-of-stripes
  
  Specifies the number of stripes to create.
  
  components-per-stripe
  
  Specifies the number of components each stripe should have.
  
  component-names
  
  Specifies the names of the components that are used. If more than one component is used, separate each component with a space.
  
  For more information, see the metainit(1M) man page.
Edit the /etc/vfstab file so that the file system references the name of the concatenation.
Remount the file system.
```
# mount /filesystem
```

Example 9-5 Expanding a File System by Creating a Concatenation

# umount /docs
# metainit d25 2 1 c0t1d0s2 1 c0t2d0s2
d25: Concat/Stripe is setup
(Edit the /etc/vfstab file so that the file system references the volume d25 instead of slice c0t1d0s2)
# mount /docs

This example shows the creation of a concatenation, d25, out of two slices, /dev/dsk/c0t1d0s2 (which contains a file system mounted on /docs) and /dev/dsk/c0t2d0s2. The file system must first be unmounted. Note that the first slice in the metainit command must be the slice that contains the file system. If not, you will corrupt your data.

Next, the entry for the file system in the /etc/vfstab file is changed (or entered for the first time) to reference the concatenation. For example, initially, the following line appears in the /etc/vfstab file:

/dev/dsk/c0t1d0s2 /dev/rdsk/c0t1d0s2 /docs ufs 2 yes -

This line should be changed to the following:

/dev/md/dsk/d25 /dev/md/rdsk/d25 /docs ufs 2 yes -

Finally, the file system is remounted.

How to Expand an Existing RAID-0 Volume

A concatenated stripe enables you to expand an existing stripe. For example, if a stripe has run out of storage capacity, you convert it into a concatenated stripe. Doing so allows you to expand your storage capacity without having to back up and restore data.

This procedure assumes that you are adding an additional stripe to an existing stripe.

Before You Begin

Check Prerequisites for Creating Solaris Volume Manager Components and Background Information for Creating RAID-0 Volumes.

To create a concatenated stripe, use one of the following methods:
- From the Enhanced Storage tool within the Solaris Management Console, open the Volumes node. Choose Action⇒Create Volume, then follow the instructions in the wizard. For more information, see the online help.
- To concatenate existing stripes from the command line, use the following form of the metattach command:
```
# metattach volume-name component-names
```
  volume-name
  
  Specifies the name of the volume to expand.
  
  component-names
  
  Specifies the names of the components that are used. If more than one component is used, separate each component with a space.
  
  See the metattach(1M) man page for more information.

Example 9-6 Creating a Concatenated Stripe by Attaching a Single Slice

# metattach d2 c1t2d0s2
d2: components are attached

This example illustrates how to attach a slice to an existing stripe, d2. The system confirms that the slice is attached.

Example 9-7 Creating a Concatenated Stripe by Adding Several Slices

# metattach d25 c1t2d0s2 c1t2d1s2 c1t2d3s2
d25: components are attached

This example takes an existing three-way stripe, d25, and concatenates another three-way stripe to it. Because no interlace value is given for the attached slices, the stripes inherit the interlace value configured for d25. The system verifies that the volume has been set up.